1. Field of the Invention
The invention relates generally to a dentifrice composition and more particularly to a dentifrice composition which contains reactive ingredients and exhibits improved anticalculus properties.
2. The Prior Art
It has been found to be very desirable to incorporate peroxide compounds in dentifrice compositions, the efficacy of peroxide compounds in oral hygiene having long been recognized. Such compounds have been proven effective in the treatment of gingivitis, periodontitis and in combating plaque. Additionally, peroxide compounds have been utilized for oral cosmetic purposes such as tooth whitening which results from bleaching and cleansing of tooth surfaces. Examples of the prior art disclosing peroxide containing dentifrices are found in the disclosures of U.S. Pat. No. 4,971,782, U.S. Pat. No. 4,897,258 and U.S. Pat. No. 4,837,008.
Although the presence of peroxide ingredients in the dentifrice provides antiplaque and whitening efficacy, an improvement in the anticalculus (i.e., antitartar) efficacy of the dentifrice is desired by the art.
Included in the wide variety of chemical agents disclosed by the prior art as being effective as anticalculus agents are the water soluble polyphosphate and pyrophosphate salts. For example, U.S. Pat. No. 4,923,684 and U.S. Pat. No. 4,985,236 disclose the use of a water-soluble alkali metal tripolyphosphate as an anticalculus agent in dentifrice compositions. The patent discloses that to be storage stable, the tripolyphosphate salt must be incorporated in the dentifrice at a concentration of at least 4% by weight, the dentifrice having an alkaline pH, for example, a pH of 8-10. At concentrations less than 4% by weight, for example, 3% by weight, the patent teaches that the polyphosphate salt is unstable in the stored dentifrice composition.
U.S. Pat. No. 4,684,518 discloses that water soluble alkali metal pyrophosphate salts are effective as anticalculus agents when present in dentifrice compositions at a concentration sufficient to provide at least 1.5% P.sub.2 O.sub.7.sup.-4 anion.
U.S. Pat. No. 5,176,900 discloses a dentifrice composition containing an anticalculus combination of a water soluble tripolyphosphate salt sufficient to provide 0.5-7.5% P.sub.3 O.sub.10 anion and a water soluble orthophosphate salt sufficient to provide from 0.2-5% orthophosphate anion, the combination being storage stable at a pH below 8.0.